The present invention relates to an interface device, and more particularly to a device for connecting a user station of a communications system, for example, a programmable controller, to a two-wire line bus.
In previous devices for connecting a user station of a communications system to a two-wire line bus, the connection means have been integrated into the circuitry of the user station. For example, in the case of modules, the means of connection is incorporated in the architecture. However, coupling such a connection means to the two-wire line bus is quite cumbersome. Under certain conditions, installing the connection means is impractical or impossible because of a lack of space. Therefore these modules do not easily connect a user station of a communication system to a two-wire line bus. Furthermore, there is no simple means of multiplying the interfaces.